October 6, 2011 AT 9:13 pm

DE0-Nano power efficiency mod

I recently bought a DE0-nano FPGA development board, which I’m currently using to mine Bitcoins. It’s kind of a neat board, but one downside to it is that it uses linear regulators to provide the 1.2V core supply to the FPGA, and they’re incredibly inefficient at this. Only about 25% of the power supplied to them actually goes into the 1.2V supply; the other 75% is wasted as heat in the regulators. Since Bitcoin mining is very power-hungry, an awful lot of the power usage is in the 1.2V core supply and the regulators get really hot.
Fortunately, it’s possible to mod the board to use a more efficient external buck regulator to supply the 1.2 volts required by the FPGA core logic. (In theory this should even allow USB-powered mining; in practice this doesn’t seem to work for some reason.) If you look at the schematics, each of the main voltages on the board (ground, the supply voltage, 3.3V, and 1.2V) is brought out to a pair of pins on the 4-pin jumpers J5 and J6. There’s also a handy zero-ohm resistor across the input to the 1.2V regulator that can be removed to disable it.

DE0-Nano – Altera Cyclone IV FPGA starter board. For every day projects, microcontrollers are low-cost and easy to use. But when you have a project that needs raw power and high speed you may want to check out FPGAs (Field Programmable Gate Arrays). FPGAs are like raw chips that you can design by hand. They run very fast and very efficiently. They are designed for mass-parallel execution so they’re very good at handling a lot of I/O pins at once, especially for real time video or audio or emulation applications.

FPGAs are also a lot of fun, in that you really get to play with how chips are designed. Unfortunately, we didn’t study FPGA’s in school and so we missed out on learning how to use them. When we saw this Altera starter pack, we thought it would be a great first FPGA board – compact but not ‘bare bones’ – at a great price! There’s no paper book included, but there is a very detailed Altera FPGA training curriculum that a student could use as part of a self-taught FPGA adventure.

The package comes with a single DE0 Nano development board, mini USB cable (you can program and power the module over USB) and two CDs with the software necessary to ‘compile’ and ‘upload’ code to the board. The software is available for Windows and Linux computers (no Mac)